# Useful function to make graphing easier
plotline <- function(output,i,lty=1,col="black",lwd=1,...){
  # This function takes output from multipleOLS
  # and plots line segments
  x0 = output[i,5]
  x1 = output[i,5]
  y0 = output[i,3]
  y1 = output[i,4]
  out <- segments(x0,y0,x1,y1,lty=lty,col=col,lwd=lwd)
  return(out)
}